The present invention relates generally to the field of envelope inserting machines, and more particularly to an envelope ejection mechanism for such machines which ejects envelopes after completion of the operation that places insert material into the envelopes.
Envelope inserting machines, sometimes referred to as envelope stuffing machines, have long been well known and have been well received in various type of business operations which involve some form of high volume mailing, although in recent years some envelope inserting machines have been designed and produced for what would be considered medium volume mailing operations. Some examples of high volume mailing operations where the present invention would find utility are various types of customer billing operations, such as bank credit, major oil company credit cards, department store charge cards, sweepstakes operations, various forms of mass mailing advertising, and myriad other operations where various items of material are inserted into an envelope for an addressee.
In a typical inserting operation, a package of insert material may include a customer bill, an advertising circular or flyer, a promotional coupon and a return envelope for the customer's convenience in paying his bill. These items are typically stored in the storage trays of a collating machine and are fed serially onto a conveyor to a location where they are stacked in a desired manner and formed into the insert package, which is then fed to a standby location in an envelope inserting machine, which may be a separate module or may be physically incorporated into the collating machine. In either event, a plurality of envelopes are stored in a storage tray of the envelope machine, and a suitable conveying mechanism conveys them seriatim to a location where packages of insert material are to be inserted into successive envelopes. The inserting machine typically includes an envelope throat opening mechanism by which the upper free edge of the envelope is spread away from the adjacent edge to which the envelope flap is attached to provide sufficient space for the package of insert material to be inserted into the envelope by a suitable inserting mechanism, such as by cooperating feed rollers or rollers and belts which engage the package of insert material to feed it into the envelope. When the envelope is filled, the throat opening mechanism disengages from the upper free edge of the envelope, and an ejection mechanism engages the envelope to withdraw it from the inserting machine and deposit it in a suitable receptacle or conveyor for further processing.
In heretofore known envelope inserting machines, the mechanism for conveying the envelopes from the storage location to the inserting location, and the ejection mechanism which withdraws the filled envelopes from the inserting machine, have each been driven by separate drive means operated by separate sources of power. For example, the conveying mechanism typically included a series of feed rollers and cooperating back up rollers mounted on shafts, one of which was typically driven by means of belts and pulleys from a suitable electric motor. Similarly, the ejection mechanism also consisted of a plurality of feed rollers and cooperating back up rollers mounted on shafts, again one of which was typically driven by means of belts and pulley from another electric motor.
In order for the envelopes to be conveyed from the storage location to the inserting location, held thereat while the insert material was being inserted by the inserting mechanism, and then be withdrawn from the inserting machine by the ejection mechanism, all in rapid sequence, some form of timing control was provided so that a succeeding envelope could be conveyed from the storage location to the insert location while a preceding envelope was being withdrawn from the inserting machine. The timing of operation of these individual mechanisms was critical to smooth operation of the inserting machine, for the reason that if any one of these mechanisms either commenced or ceased operation either before or after a critical time, a jam would occur in the machine which almost invariably caused the machine to cease operation until an operator could clear the jammed envelope and insert material package. In view of the fact, as stated above, that these machines are most typically used in large volume mailing operations where speed and continuity of operation are extremely important to maintaining a cost effective operation, it is apparent that proper timing of operating periods of the individual mechanisms of the inserting machine is of major importance.
Thus, there is a need for an improvement in the envelope ejection mechanisms of known inserting machines which eliminates the necessity for providing any form of control device or instrumentality for maintaining critical timing control over the various mechanisms utilized in the inserting machines for performing the above described functions which will effectively eliminate the forgoing problems.